Low impact auxiliary switch mechanically operated contacts (MOC) mechanism

An auxiliary switch actuator for a circuit breaker, comprising:

• a crank arm of an auxiliary rotary switch in the circuit breaker, configured to change electrical connections of contacts in the auxiliary rotary switch when the crank arm is rotated about an axis of the crank arm, a rotation of the crank arm about the axis of the crank arm in a first rotary direction being limited to a rotation limit by a limit stop;
• a crank spring connected to the crank arm at an end opposite to the axis of the crank arm, the crank spring having a spring bias configured to apply a force to the crank arm to impart a rotary motion to the crank arm about the axis in the first rotary direction to rotate the auxiliary rotary switch;
• a connection-state link in the circuit breaker, having an aperture in the connection-state link with an edge configured to contact a crank pin mounted on the crank arm at the end opposite to the axis of the crank arm, the crank pin configured to apply a force on the edge of the aperture of the connection-state link in response to the spring bias of the crank spring;
• wherein the connection-state link is contacted by a drive link coupled to main contacts of the circuit breaker, the drive link configured to apply a force to the connection-state link in response to closure of the main contacts of the circuit breaker to move the connection-state link in a first direction, to thereby reduce the force by the crank pin on the edge of the aperture of the connection-state link and enable the crank arm to impart the rotary motion to the crank arm about the axis in the first rotary direction to rotate the auxiliary rotary switch corresponding to the closure of the main contacts of the circuit breaker;
• wherein the limit stop is configured to limit the rotation of the crank arm in the first rotary direction to the rotation limit while the edge of the aperture of the connection-state link continues to move in the first direction to cause the edge of the aperture in the connection-state link to cease contact with the crank pin mounted on the crank arm, to thereby decouple the connection-state link from the crank arm, to relieve the crank arm of forces resulting from the main contacts of the circuit breaker closing;
• wherein the connection-state link comprises a first end proximate to the crank spring and a second end distal to the crank spring;
• wherein a force applied in a direction from the second end of the connection-state link to the first end of the connection-state link is defined as an upward directed force applied in an upward direction;
• wherein the edge of the aperture of the connection-state link is an edge proximate to the first end of the connection-state link and is defined as an upper edge of the aperture;
• wherein the force applied by the spring bias of the crank spring to the crank arm is an upward directed force;
• wherein the force applied by the crank pin to the edge of the aperture of the connection-state link is an upward directed force;
• and
• wherein the force applied by the drive link to the connection-state link is an upward directed force to move the connection-state link in the upward direction.

A circuit breaker, comprising:

• an auxiliary rotary switch in the circuit breaker, configured to indicate a state of main contacts of the circuit breaker as being open or closed;
• a crank arm of the auxiliary rotary switch in the circuit breaker, configured to change electrical connections of contacts in the auxiliary rotary switch when the crank arm is rotated about an axis of the crank arm, a rotation of the crank arm about the axis of the crank arm in a first rotary direction being limited to a rotation limit by a limit stop;
• a crank spring connected to the crank arm at an end opposite to the axis of the crank arm, the crank spring having a spring bias configured to apply a force to the crank arm to impart a rotary motion to the crank arm about the axis in the first rotary direction to rotate the auxiliary rotary switch;
• a connection-state link in the circuit breaker, having an aperture in the connection-state link with an edge configured to contact a crank pin mounted on the crank arm at the end opposite to the axis of the crank arm, the crank pin configured to apply a force to the edge of the aperture of the connection-state link in response to the spring bias of the crank spring;
• wherein the connection-state link contacts a drive link coupled to main contacts of the circuit breaker, the drive link configured to move the connection-state link in response to closure of the main contacts of the circuit breaker, to thereby reduce the force applied by the crank pin to the edge of the aperture of the connection-state link and enable the crank arm to impart the rotary motion to the crank arm about the axis in the first rotary direction to rotate the auxiliary rotary switch corresponding to the closure of the main contacts of the circuit breaker;
• and
• wherein the limit stop is configured to limit the rotation of the crank arm in the first rotary direction to the rotation limit while the edge of the aperture of the connection-state link continues to move and to cause the edge of the aperture in the connection-state link to cease contact with the crank pin mounted on the crank arm, to thereby decouple the connection-state link from the crank arm, to relieve the crank arm of forces from the drive link resulting from the main contacts of the circuit breaker closing.